1. Field of the Invention
The present invention relates to a flat rotary electric generator and, more specifically to a flat rotary electric generator which generates a current by using at least one core-less helically-wound toroidal coil structure to cut magnetic lines generated by at least one coaxial disc-shaped pole structure so as to reduce the size and increase the efficiency of the generator.
2. Description of the Related Art
An electric generator is a machine which converts magnetic energy into electrical energy and basically utilizes Faraday""s Law and Lenz""s Law to effect the generation of electricity.
There are a wide variety of electric generators; however, in general, the electric generators are classified into rotary electric generator systems and linear electric generator systems.
In a common type of rotary electric generator, the windings (stators) thereof are distributed around a circle and a magnetic rotor is provided at the center thereof. In order to operate the electric generator, magnetic lines are introduced by the windings into a permeable material such as, for example, a silicon steel sheet or core inside the windings. However, this will generate an attractive force between the magnetic rotor and the permeable material and therefore cause a resistant force against the rotation of the rotor. This resistant force can be decreased by shortening the distance between the permeable material and the rotor, but in that case the number of magnetic lines crossed is decreased, and therefore there will be no increase in the induced electromotive force.
As described above, the conventional electric generator utilizes rotation of the magnetic rotor to generate an induced current on the winding of the stator. However, the conventional electric generator of a silicon steel sheet or other magnetically permeable core as a medium for the magnetic lines of force increases the weight of the generator and results in eddy current loss that may increase the torque in operation. Additionally, the core magnetic loss and eddy current loss in the permeable material may also reduce the efficiency for generating the electricity. As result, the efficiency of the conventional generator is too low for practical use as a mini-electric generator. In order to solve the above disadvantages, it is necessary to develop a flat electric generator with high efficacy which is applicable as a mini-electric electric generator and in compliance with the requirement for a light, thin, short and small electric generator.
In view of the above problems, the object of the invention is to provide a flat rotary electric generator capable of generating a current by using a helically-wound toroidal coil structure to cut magnetic lines generated by a coaxial rotary disc-shaped magnetic pole structure.
For achieving the above object according to an aspect of the invention, a flat rotary electric generator is provided, comprising: at least one toroidal coil structure for cutting magnetic lines to induce a current; at least one disc-shaped magnetic pole structure oriented in parallel with the toroidal coil structure and located on the side of the toroidal coil structure, wherein the magnetic lines produced by the at least one disc-shaped magnetic pole structure can pass through the at least one toroidal coil structure, when the disc-shaped magnetic pole structure is rotated by an external force such as mechanical force, hydraulic force or wind force, and the toroidal coil can cut the magnetic lines passing therethrough to generate an induced current.
Further, according to another aspect of the invention, the electric generator has no silicon steel sheet or other magnetically permeable core.
Further, according to another aspect of the invention, the electric generator includes a plurality of toroidal windings and disc-shaped pole structures which are arranged in alternating and parallel manner.
Further, according to another aspect of the invention, the at least one disc-shaped pole structure includes at least two magnetic poles arranged in alternating fashion, or pairs of alternating poles arranged in series.
Further, according to another aspect of the invention, magnets of the disc-shaped magnetic pole structure can comprise separate pole structures joined to form a disc, or a single disc-shaped structure magnetized to form the poles.
Further, according to another aspect of the invention, the toroidal coil structure is fixed and the disc-shaped magnetic pole structure is arranged to rotate, or the disc-shaped magnetic pole structure is fixed and the toroidal coil structure is arranged to rotate and the toroidal coil structure and the disc-shaped magnetic pole structure are co-axial.
Thus, the invention is capable of solving the disadvantages of a conventional rotary electric generator, such as the low efficiency, high cost, and large size caused by the use of permeable material in the conventional generator.